The present invention relates to a quick disconnect coupling and more particularly to a plug for a quick disconnect coupling for coupling a high-pressure air hose.
Conventionally, air compressors via quick disconnect couplings connect to hoses of pneumatic tools by providing a socket for such a quick disconnect coupling on the air compressor side and providing the hose with a plug adapted for the quick disconnect coupling, so that the hose is made detachable from the air compressor in a one-touch mode. When the plug is put in the socket, the leading end of the plug opens the self-seal valve of the socket, whereby the plug and the socket are simultaneously coupled together. The hose is removable from the socket by sliding the lock ring of the socket to let the plug come off the socket. The self-seal valve of the socket is then closed.
When the hose connected to the air compressor is removed, however, the hose may throb like a whip and injure persons or damage commodities nearby due to the reaction force of pressurized air gushing out of the plug of the hose connected to the terminal unit of the pneumatic tool.
If the pressurized air in the hose is hermetically sealed up by providing the plug with the self-seal valve to prevent the air from gushing out of the plug, the terminal unit may be driven with the pressurized air sealed in the hose in such a state that the hose has been detached from the air compressor. However, while a box nailing machine, for example, is being operated, it is still liable to cause an accident.